OPANA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for OPANA (OPANA).
Mu-opioid receptor agonist; produces analgesia by binding to opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception.
| Metabolism | Hepatic via CYP3A4 and CYP2C8 to noroxymorphone and oxymorphone; also undergoes glucuronidation. |
| Excretion | Primarily renal (approximately 90% as conjugated metabolites, 10% unchanged); biliary/fecal elimination accounts for <10%. |
| Half-life | Terminal elimination half-life is 11-16 hours (mean 14 hours) in adults; prolonged in hepatic impairment (up to 30 hours) and elderly. |
| Protein binding | Approximately 91-94% bound, primarily to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Vd ~ 3.3 L/kg (range 2.5-4.1 L/kg), indicating extensive tissue distribution. |
| Bioavailability | Oral: ~48% (range 31-54%) due to first-pass metabolism; intranasal: ~46% (comparable to oral); intravenous: 100%. |
| Onset of Action | Oral immediate-release: 30-60 minutes; intravenous: 5-10 minutes; intranasal: 10-15 minutes. |
| Duration of Action | Oral immediate-release: 4-6 hours; extended-release: 12 hours (analgesic effect); intravenous: 3-4 hours. |
5-20 mg orally every 4-6 hours as needed for pain; extended-release tablets: 5 mg orally every 12 hours, titrated up to 20 mg every 12 hours.
| Dosage form | INJECTABLE |
| Renal impairment | GFR 30-59 mL/min: reduce dose by 25-50%; GFR <30 mL/min: reduce dose by 50% and extend dosing interval to every 12 hours; avoid use in dialysis. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce starting dose by 50%; Child-Pugh Class C: avoid use. |
| Pediatric use | Not recommended for pediatric patients under 18 years of age; safety and efficacy not established. |
| Geriatric use | Start at the lower end of the dosing range (2.5-5 mg every 4-6 hours) and titrate cautiously; monitor for respiratory depression and constipation. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for OPANA (OPANA).
| Breastfeeding | Breastfeeding safety: Oxymorphone is excreted in breast milk. The M/P ratio is approximately 2.0 (based on limited data). Caution is advised due to potential for infant sedation and respiratory depression. Use only if benefit outweighs risk, and monitor infant for signs of opioid toxicity. |
| Teratogenic Risk | Teratogenic risk profile for OPANA (oxymorphone): First trimester: Limited human data; animal studies show no evidence of teratogenicity at clinically relevant doses. Second and third trimesters: Chronic use may cause fetal opioid dependence and neonatal withdrawal syndrome. Use during labor may cause respiratory depression in the neonate. |
■ FDA Black Box Warning
Addiction, abuse, and misuse; life-threatening respiratory depression; neonatal opioid withdrawal syndrome; risks from concomitant use with benzodiazepines or other CNS depressants.
| Serious Effects |
Hypersensitivity to oxymorphone or any component; significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment; known or suspected gastrointestinal obstruction including paralytic ileus; concurrent use of MAOIs or within 14 days of such therapy.
| Precautions | Respiratory depression; CNS depression; hypotension; adrenal insufficiency; serotonin syndrome; constipation; urinary retention; seizures; increased intracranial pressure; biliary tract spasm; tolerance; physical dependence; withdrawal; impaired mental/physical abilities; risk of death with alcohol or other CNS depressants; elderly/cachectic patients; renal/hepatic impairment; pregnancy; labor and delivery; breastfeeding. |
Loading safety data…
| Fetal Monitoring | Required clinical monitoring: Maternal: Monitor for respiratory depression, sedation, constipation, and signs of opioid abuse. Fetal/neonatal: Monitor for fetal distress in utero and neonatal withdrawal syndrome (e.g., irritability, poor feeding, seizures) after delivery. Consider fetal heart rate monitoring during labor if used. |
| Fertility Effects | Reproductive impact: Opioids may cause hormonal changes, including decreased libido and potential for anovulation due to suppression of gonadotropin-releasing hormone. Animal studies show no direct impairment of fertility at therapeutic doses, but chronic use may disrupt menstrual cycles. |